Electrostatic grid



Dec'. l0, 1968 K. E. RoBERTs ET Al. 3,415,222

ELEGTROSTATIC GRID Filed March 20, 1967 n: im

3% @m n IL Y N Q l-I- |Nv ToR KENNETH E. ROBERTS s' BSEoRcsE E. coRNEAu wt?" ATTORNEY United States Patent O 3,415,222 ELECTROSTATIC GRID Kenneth E. Roberts, Riverside, and George E. Corneau, Central Falls, R.I., assignors to Indev, Inc., Pawtucket, RJ., a corporation of Rhode Island Filed Mar. 20, 1967, Ser. No. 624,552 5 Claims. (Cl. 118-636) ABSTRACT OF THE DISCLOSURE The present invention relates to improvements in flocking machines and more particularly to an improved high voltage grid for use in Hocking machines.

An object of the present invention relates to improvements in flocking machines in which high voltage grids are employed to produce an electrostatic field and wherein the grids are adapted to A.C. power usage.

Another object of the present invention is to provide an improved flocking machine in which grids are employed to produce an electrostatic field and wherein the grids are of novel design practically obviating the use of metal.

A further object of the present invention is to provide an improved ocking machine in which grids are employed to produce an electrostatic field and wherein the grid is so constructed as to provide faces adapted to shed ock and thereby prevent ock collection on the grid.

A still further object of the present invention is to provide an improved grid for use in flocking machines wherein the grid employs a conductive fluid rather than a metal plate for improved production of the electrostatic eld.

Still another object of the present invention is to provide an improved grid for use in tiocking machines wherein the grid casing is constructed of lightweight insulating material having a cross-sectional design which provides a shaped surface for shedding flock.

Another object of the present invention is to provide an improved grid for use in dlocking machines wherein the support thereof is such as to maintain a substantially horizontal condition throughout its relatively long length.

Various other objects and advantages will become apparent from the detailed description to follow.

In the drawings:

FIGURE 1 is an elevational view showing one of the grids of the present invention and its support.

FIGURE 2 is a transverse sectional view through a series of grids and showing one form of drive therefor.

Flocking machines are lof various types as are well known in the art. An example is shown in Patent No. 2,992,126 for Flocking Machine and Method issued to Kenneth Roberts and Silas Carlyle Peterson. The description contained in that patent is incorporated herein by reference. It will be understood however, that the grid of the present invention can be utilized in a variety of flocking machines.

The grid comprises a tubular member containing a conductive lluid to which an A.C. current is applied and 3,415,222 Patented Dec. 10, 1968 ice wherein drive means is included which continuously rotates or oscillates the tube to prevent iiock collection thereon. The grid also includes a special cantilever support for maintaining the axis of the tube substantially straight.

Referring more particularly to the drawings wherein like numerals apply to like parts throughout, it will be seen that we have provided in a iiocking machine which includes a series of supply hoppers 12 for ock F, a series of transverse grids 14 which produce an electrostatic iield through the sheet or other object 16 to which the flock is applied.

Flock F can be of any desired characteristics; the length, diameter, color and other features are varied according to the desired end product, as is well known in the art.

The Hock F is carried in the supply hoppers 12 which continuously dispense the ilock over the article 16 during operation of the machine. The article 16 is moved through the machine along a path between the series of upper and series of lower grids 14. The article has an adhesive coating in any area where it is desired to bond the flock, asis understood.

The grids are charged to function to produce a field of force between the upper and lower grids whereby the flock is oriented relative to the article preparatory to bonding thereto, as will now be described.

The grids 14 are substantially of identical design so a description of one is deemed to suice for all.

Each grid 14 is comprised of an elongated tubular assembly 18 having end connections 20 of similar design and support means 22 with electrical circuitry at 24.

Each tubualr assembly includes an inner tube 26 made of a suitable plastic material such as polyvinylchloride (PVC) or berglass. The ends of tube 26 are threaded into elbow 28 and has a ring 30 non-movably mounted on each end. Elbow 28 has riser 32 connected to its opposing end with end cap 34 thereon. Suitable conductive iluid such as water is contained in the tube 26 and riser 32 as shown at 36.

At several points along its length, the tube 26 has bearing strips wrapped therearound. For example, Teflon tape or other low friction tape can be utilized as Ishown at 38.

The outer tube 40 is rotatably supported on the tapes 38 about the inner tube. The ends of tube 40 are retained from axial movement by the rings or thrust collars 30. Theouter tube material can be of butyrate or similar material.

The support means 22 is comprised of a bar 40 engaged through large vpipe 42 which extends longitudinally of the machine at the ends of the grids. The risers 32 extend through and are rigidly attached to the pipe 42. The bar 40 engages through pipe 42 so that lifting of the end 40 of the bar tends to rotate pipe 42 counterclockwise along with the riser thus acting to support the pipe 18 as a cantilever but urging it to arc upwardly. Thus the force of gravity which would otherwise tend to cause the pipe to arcuate dowwardly is counteracted. The bar 40 is supported by cable 44 anchored at its upper end to a part of the machine.

The electrical circuitry 24 simply comprises a wire terminating in a coil 46 immersed in the fluid 36 and connected to an A.C. high voltage source (not shown).

The drive means for eiecting oscillation or rotation of the grid can assume a variety of forms. For example, a cable 47 can be engaged around all of the sleeves or outer pipes 40 and then passed over sheaves 48, 50 with a weight at one end and a motor M at the other end having an eccentric drive as shown. It will be obvious that rotation of the disk 52 by motor M will cause cable 47 first to travel in one direction and then in the opposite direction. The sleeves or outer pipes40 thus oscillate shedding flock thereon.

Continuous rotation in a common direction can also be effected, if deisred, by means such as belt drives (not shown) passed over each pipe.

The flocking machine usually contains upper and lower grids. The upper grids may all be connected to an A.C. high voltage source and the lower grids grounded or the connections above and below the article can be alternately connected to such source and ground.

In any case, the grids produce an electrostatic field which acts in a highly efficient manner to orient the fibers of ock in relation to the article.

It will be understood that the grids do not employ any metal components except for the wire connections in the elbow tubes so that the high voltage charge does not concentrate in any specific location or cause arcs or shorting.

In view of the foregoing, it is believed that we have provided an improved grid and flocking machine which fulfill the objects hereinbefore enumerated.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by these claims.

What is claimed is:

1. In a flocking apparatus wherein fibrous pile is applied to an adhesive surface of an article as it is moved along a plane through the apparatus, said apparatus including supply means for holding a supply of flock over the adhesively coated surface, and two electrical conducting systems, one disposed above the plane of movement of said article and the second disposed below said plane of movement, one of said systems being grounded and the other of said systems connected to a source of alternating current, the improvement wherein the conductor system above said plane of movement comprises a series of elongated, fluid-tight, rounded tubular members of a selected non-conductive material, a body of conductive liquid in each said member, and terminal means for connecting each said body of conductive liquid to an electric circuit, said terminal means including a connecting tube having a body of electrically conductive liquid therein in communication with the body of electrically conductive fluid in the tubular member, and a wire end immersed in each said connecting tube and connected to an electric circuit.

2. The apparatus of claim 1 wherein said conductive fluid is water.

3. The apparatus of claim 1 wherein said tubular members are arranged in parallel.

4. The apparatus of claim 3 wherein said elongated tubular members are arranged perpendicular to the direction of movement of said article through the apparatus.

5. The apparatus of claim 1 wherein said rounded tubular members are of circular cross-section.

References Cited UNITED STATES PATENTS Re. 20,660 2/1938 Schacht 118-638 XR 2,245,301 6/1941 Schacht 118-638 XR 2,394,657 2/1946 Beregh 118-636 XR 2,742,018 4/1956 Lindquist 118-636 3,058,443 10/1962 Paton 11S-636 XR 3,114,482 12/1963 Dunaway 118-636 3,221,938 12/1965 Yonkers et al. 118--636 PETER FELDMAN, Primaly Examiner.

U.S. Cl. X.R. 117-17; 317-3 

